// Copyright (c) 2021 Presto Labs Pte. Ltd.
// Author: fengyang

#pragma once

#include <algorithm>
#include <functional>
#include <limits>
#include <map>
#include <string>
#include <vector>
#include <utility>

#include "coin2/base/string_util.h"
#include "coin2/exchange/base/feed/processor.h"
#include "coin2/exchange/feed.pb.h"
#include "coin2/exchange/gdax/api_util/auth_key.h"

namespace coin2::exchange::gdax::feed_v1 {
namespace impl {

using coin2::exchange::feed::WebsocketConfig;

class GdaxRequestGenerator : public base::feed::RequestGenerator {
 public:
  explicit GdaxRequestGenerator(const WebsocketConfig* ws_config)
      : config_(ws_config) {
    if (config_->key_filepaths_size() > 0) {
      auth_ = std::make_unique<GdaxWsAuth>(config_->key_filepaths(0));
    }
  }

  std::vector<std::string> GenerateRequests(
      const std::vector<std::string>& channels,
      const std::vector<std::string>& symbols,
      const std::map<std::string, std::string>& channel_templates,
      const std::string& request_template) override {
    std::vector<std::string> reqs;
    std::vector<std::string> ch = channels;
    std::vector<std::string> ch_kline;
    auto iter = ch.begin();
    while (iter != ch.end()) {
      if (StringStartsWith(*iter, "kline_rest")) {
        ch_kline.push_back(*iter);
        iter = ch.erase(iter);
      } else {
        iter++;
      }
    }
    if (!ch_kline.empty()) {
      auto timestamp = MarketTimestampProvider::GetTimestamp();
      boost::posix_time::ptime round_time = TimestampRoundHour(timestamp);
      for (auto& ch_k : ch_kline) {
        std::string c = channel_templates.at(ch_k);
        auto interval_time = GetGranularity(c);
        for (auto& symbol : symbols) {
          std::vector<std::pair<int64_t, int64_t>> durations;
          bool long_query = base::feed::RequestGenerator::CheckLongQuery(
              round_time, symbol, ch_k, &last_long_query_time_);
          if (long_query) {
            // gdax request limitation is 300
            durations = base::feed::RequestGenerator::GetDurations(
                config_->kline_length(), config_->kline_start(), config_->kline_end(),
                interval_time, 250);
          } else {
            // query small data
            durations = base::feed::RequestGenerator::GetDurations(
                "3", "", "",interval_time, 250);
          }
          int idx = 0;
          for (auto& d : durations) {
            std::string c_copy = c;
            boost::replace_all(c_copy, "{}", symbol);
            boost::replace_all(c_copy, "{end}", std::to_string(d.second / 1'000'000'000LL));
            boost::replace_all(c_copy, "{start}", std::to_string(d.first / 1'000'000'000LL));
            if (long_query) {
              c_copy.append("&page=").append(std::to_string(idx));
            }
            reqs.emplace_back(c_copy);
            idx++;
          }
        }
      }
    }

    if (!ch.empty()) {
      std::vector<std::string> reqs_others;
      std::vector<std::string> channels_reqs;
      for (const auto& channel_name : channels) {
        for (const auto& symbol : symbols) {
          std::string c = channel_templates.at(channel_name);
          boost::replace_all(c, "{}", symbol);
          channels_reqs.push_back(c);
        }
      }
      std::string merged = boost::algorithm::join(channels_reqs, ", ");
      std::string s = request_template;
      boost::replace_all(s, "{channel}", merged);
      if (auth_ != nullptr) {
        auto sign_list = auth_->GetSignatureStringList();
        std::vector<std::string> sign_vector{
          std::make_move_iterator(std::begin(sign_list)),
          std::make_move_iterator(std::end(sign_list))};
        auto auth_str = fmt::format(
            R"(, "key": "{}", "passphrase": "{}", "timestamp": "{}", "signature": "{}")",
            sign_vector[0],
            sign_vector[1],
            sign_vector[2],
            sign_vector[3]);
        boost::replace_all(s, "{auth}", auth_str);
      } else {
        boost::replace_all(s, "{auth}", "");
      }
      reqs_others.push_back(s);

      reqs.insert(reqs.end(), reqs_others.begin(), reqs_others.end());
    }

    return reqs;
  }

 private:
  std::string ToKlineTimeString(int64_t timestamp) {
    return Iso8601FromTimestamp(timestamp);
  }

  int64_t GetGranularity(const std::string& channel) {
    if (channel.find("granularity=60") != std::string::npos) {
      return (int64_t)60 * 1'000'000'000;
    } else if (channel.find("granularity=300") != std::string::npos) {
      return (int64_t)300 * 1'000'000'000;
    } else if (channel.find("granularity=900") != std::string::npos) {
      return (int64_t)900 * 1'000'000'000;
    } else if (channel.find("granularity=3600") != std::string::npos) {
      return (int64_t)3600 * 1'000'000'000;
    } else if (channel.find("granularity=86400") != std::string::npos) {
      return (int64_t)24 * 3600 * 1'000'000'000;
    } else {
      THROW() << "Unkonw new channel: " << channel;
    }

    return std::numeric_limits<int64_t>::quiet_NaN();
  }

  const WebsocketConfig* config_;
  std::unique_ptr<GdaxWsAuth> auth_;
};

}  // namespace impl
using impl::GdaxRequestGenerator;
}  // namespace coin2::exchange::gdax::feed_v1
